Get device unique identifier (UDID, DeviceID...) under Android

http://blog.csdn.net/langresser_king/article/details/9373051

1. Under normal circumstances, it can be obtained through ((TelephonyManager) s_instance.getSystemService( Context.TELEPHONY_SERVICE )).getDeviceId();, but this function will return null for some tablets

2. An id can also be obtained through Secure.getString(s_instance.getContentResolver(), Secure.ANDROID_ID);, but it is also problematic for android2.2 or some cottage phones to use this, it will return a fixed value 9774d56d682e549c

3. If the first two do not get the udid, then create a random uuid when the program starts, and then save it. This is a compatible solution, of course, there are not many such devices.

or OpenUDID

https://github.com/vieux/OpenUDID

 

protected static final String PREFS_FILE = "gank_device_id.xml";
    protected static final String PREFS_DEVICE_ID = "gank_device_id";
    protected static String uuid;
    /**
     * Get the unique identifier
     * @param mContext
     * @return
     */
    public synchronized static String getUDID(Context mContext)
    {
        if( uuid ==null ) {
                if( uuid == null) {
                    final SharedPreferences prefs = mContext.getApplicationContext().getSharedPreferences( PREFS_FILE, Context.MODE_PRIVATE);
                    final String id = prefs.getString(PREFS_DEVICE_ID, null );

                    if (id != null) {
                        // Use the ids previously computed and stored in the prefs file
                        uuid = id;
                    } else {

                        final String androidId = Settings.Secure.getString(mContext.getContentResolver(), Settings.Secure.ANDROID_ID);
                        // Use the Android ID unless it's broken, in which case fallback on deviceId,
                        // unless it's not available, then fallback on a random number which we store
                        // to a prefs file
                        try {
                            if (!"9774d56d682e549c".equals(androidId)) {
                                uuid = UUID.nameUUIDFromBytes(androidId.getBytes("utf8")).toString();
                            } else {
                                final String deviceId = ((TelephonyManager) mContext.getSystemService( Context.TELEPHONY_SERVICE )).getDeviceId();
                                uuid = deviceId!=null ? UUID.nameUUIDFromBytes(deviceId.getBytes("utf8")).toString() : UUID.randomUUID().toString();
                            }
                        } catch (UnsupportedEncodingException e) {
                            throw new RuntimeException(e);
                        }

                        // Write the value out to the prefs file
                        prefs.edit().putString(PREFS_DEVICE_ID, uuid).commit();
                    }
                }
        }
        return uuid;
    }